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arXiv 0912.4632cond-mat.mes-hallcond-mat.str-el
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量子点的热电输运:Kondo通道不对称性的影响

Thermoelectric Transport through a Quantum Dot: Effects of Kondo Channels Asymmetry

T. K. T. Nguyen, M. N. Kiselev, V. E. Kravtsov

摘要:

本文研究了磁场对单电子晶体管热电势和热导的影响,该晶体管由一个量子点通过单模量子点接触与其中一个引线强耦合而成。我们发现了两个新的能量标度:T_{min} ~ |r| ^2 E_C(B/B_C)^2依赖于磁场B和场B_C的比值,对应于点接触的全极化; T_{max} ~ |r| ^2 E_C依赖于反射振幅r和充电能量E_C。在T T_{min}时,热电系数的行为符合费米液体理论,而在T_{min} <T< T_{max}时,热电系数从非费米液体的双通道近藤效应过渡到费米液体的单通道近藤效应.

英文摘要:

We consider effects of magnetic field on the thermopower and thermoconductance of a single-electron transistor based on a quantum dot strongly coupled to one of the leads by a single-mode quantum point contact. We show appearance of two new energy scales: T_{min} ~ |r|^2 E_C(B/B_C)^2 depending on a ratio of magnetic field B and the field B_C corresponding to a full polarization of point contact and T_{max} ~ |r|^2 E_C depending on a reflection amplitude r and charging energy E_C. We predict that the behavior of thermoelectric coefficients is consistent with the Fermi-liquid theory at temperatures T << T_{min}, while crossover from Non-Fermi-liquid regime associated with a two-channel Kondo effect to Fermi-liquid single-channel Kondo behavior can be seen at T_{min}<T<T_{max}.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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